Molecular Dynamics Simulations of Colloidal Particles Approaching Liquid-Liquid Interfaces

 

The tendency of colloidal particles to reside at a fluid interface at equilibrium position as predicted by Young’s equation is the basic concept underlying the behavior of Pickering emulsions. Recently colloids of tunable wettability have been produced by partial modification of their surface, which yields so-called Janus particles with asymmetric surface properties. Despite the vast literature on colloidal particles at interfaces, little information is available with respect to the behavior of Janus particles and the dynamics of colloidal particles moving towards and onto an interface.  We have investigated the movement of colloids toward the interface between two immiscible fluids via Molecular Dynamics (MD) Simulations. Although micron-sized particles are used for most practical applications, we focus on nanometer-sized particles in our simulations due to computational constraints. However, our initial results show that the behavior of larger particles is captured reasonably well by the MD calculations. We present simulation results for both ordinary symmetric particles and Janus particles, and compare the results to experimental observations.